Changes of phenolic compoundsand antioxidant activity inducedby germination of vicia faba

In Mexico, the seeds of faba beans (V. faba) are a food preferably consumed in dry form. This seed has good nutritional value (proteins and carbohydrates) that contributes to the proper functioning of the human body. Moreover, it has some constituents which are considered as non-nutritive compounds and have demonstrated important biological activity, such as phenolic compounds. During seed germination changes occur (caused by the hydrolysis of reserve storage material and synthesis of components in order to produce a new plant) in the concentration, distribution and structure of phenolic compounds, thereby modifying their potential as antioxidant agents which may participate in the scavenging of various free radicals, chelation of metals or inhibition of some enzymes. Therefore, the objective of this research was to evaluate the change in the nutritional and non-nutritional composition, as well as in the biological activity of phenolic compounds during germination in the different structures (cotyledon, hull and embryonic axis) of three varieties (Col-160, Col-181 and Col-281) of V. faba. Changes in the composition of phenolic compounds were evaluated for different germination periods (0, 8, 12, 16 days), besides their antioxidant capability by different methods (ABTS, DPPH, FRAP, ORAC, and chelation of Fe and Cu). During germination, it was observed that while the total concentration of phenolic compounds remained constant in the cotyledon and decreased in the hull, this value significantly increased in the embryonic axis with time; the antioxidant activity significantly increased as well in the latter structure, unlike in the other ones, throughout the germination process. Therefore, the germination is a low cost process that can modify the composition and nutritional quality of seeds, so that germinated faba bean seeds might be used as food with potential benefit for health.